What is Self-Inductance?
Self
inductance is the property of an electric circuit that opposes any change in
current in that circuit.
inductance is the property of an electric circuit that opposes any change in
current in that circuit.
Because
it will be quite apparent from the circuit diagram whether the induction action
in question is self-inductance or mutual inductance, it is customary to omit
the self and simply speak of the inductance of an electric circuit. And since
inductance is a property of an electric circuit, we shall require a letter symbol
to represent inductance and a unit of measurement.
it will be quite apparent from the circuit diagram whether the induction action
in question is self-inductance or mutual inductance, it is customary to omit
the self and simply speak of the inductance of an electric circuit. And since
inductance is a property of an electric circuit, we shall require a letter symbol
to represent inductance and a unit of measurement.
The
letter symbol for inductance is L.
letter symbol for inductance is L.
The
henry is the SI unit of Inductance.
henry is the SI unit of Inductance.
The
unit symbol for henry is H.
unit symbol for henry is H.
In
the International System of units, since we define the ampere in terms of the
magnetic force between parallel current-carrying conductors, and the weber in
terms of the voltage induced by a changing current, magnetic units are
completely compactable with electrical units. So we can define the unit of
inductance either in terms of the change in flux resulting from a given change
in current or in terms of the induced voltage resulting from a given change in
current. The general definition of the henry is based on flux linkages. Hence,
the International System of units, since we define the ampere in terms of the
magnetic force between parallel current-carrying conductors, and the weber in
terms of the voltage induced by a changing current, magnetic units are
completely compactable with electrical units. So we can define the unit of
inductance either in terms of the change in flux resulting from a given change
in current or in terms of the induced voltage resulting from a given change in
current. The general definition of the henry is based on flux linkages. Hence,
An electric circuit has an inductance of one henry
when a change in current of one ampere produces a change in total flux linkages
of one weber.
when a change in current of one ampere produces a change in total flux linkages
of one weber.
The
total flux linkages of a multi-turn coil are N times as great as for a single
turn carrying the same current. Hence
total flux linkages of a multi-turn coil are N times as great as for a single
turn carrying the same current. Hence
Where
L is the inductance of a circuit in henry, eL is the voltage induced
into the circuit in voltd by current changing at the rate of di/dt ampere per second.
L is the inductance of a circuit in henry, eL is the voltage induced
into the circuit in voltd by current changing at the rate of di/dt ampere per second.
Thus
we can also define the magnitude of the henry completely in electrical units
without having to determine the magnetic flux.
we can also define the magnitude of the henry completely in electrical units
without having to determine the magnetic flux.
An
electric circuit has an inductance of one henry when current changing at the
rate of one ampere per second induces a voltage of one volt into the circuit.
electric circuit has an inductance of one henry when current changing at the
rate of one ampere per second induces a voltage of one volt into the circuit.